1. Field of the Invention
The present invention generally relates to lighting systems and, more particularly, to lighting systems capable of producing high-brightness, high-uniformity white light of the required color temperature.
2. The Prior Arts
Today's lighting systems, which commonly utilize incandescent lamps and halogen lamps, are simple and easy to use. However, they usually require larger input power and their lighting quality often deteriorates after long period of use. As such, new lighting systems for the next generation are continuously developed and proposed. Among them, light-emitting diode (LED) based lighting systems seem to be the most promising one, especially after the white-light LEDs are successfully developed. Under the current technology, however, the white-light LEDs are usually slightly bluish in color, expensive, and have a short operation life. LED-based lighting systems therefore are not commonly adopted yet.